Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754930Ab1DUQ2m (ORCPT ); Thu, 21 Apr 2011 12:28:42 -0400 Received: from mga03.intel.com ([143.182.124.21]:27394 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754867Ab1DUQ2k (ORCPT ); Thu, 21 Apr 2011 12:28:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,252,1301900400"; d="scan'208";a="423357767" From: Youquan Song To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, hpa@linux.intel.com, suresh.b.siddha@intel.com, yong.y.wang@linux.intel.com, joe@perches.com, jbaron@redhat.com, trenn@suse.de, kent.liu@intel.com, chaohong.guo@intel.com, Youquan Song , Youquan Song Subject: [PATCH v4 1/2] apic: Fix error interrupt report at all APs Date: Fri, 22 Apr 2011 00:22:43 +0800 Message-Id: <1303402963-17738-1-git-send-email-youquan.song@intel.com> X-Mailer: git-send-email 1.6.4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3569 Lines: 80 This patch fixes a bug reported from customer, who found many unreasonable error interrupts reported on all APs during the system boot stage. According to Chapter 10 of Intel Software Developer Manual Volume 3A, Local APIC may signal an illegal vector error when an LVT entry is set as an illegal vector value (0~15) under FIXED delivery mode (bits 8-11 is 0), regardless of whether the mask bit is set or an interrupt actually happen. These errors are seen as error interrupts. The initial value of thermal LVT entries on all APs always reads 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI sequence to them and LVT registers are reset to 0s except for the mask bits which are set to 1s when APs receive INIT IPI. When BIOS take over the thermal throttling interrupt, LVT thermal deliver mode should be SMI and it is required to restore AP's LVT thermal monitor register. This issue happens when BIOS do not take over thermal throttling interrupt, AP's LVT thermal monitor register will be restored to 0x10000 which means vector 0 and fixed deliver mode, so all APs will signal illegal vector error interrupt. This patch check if interrupt delivery mode is not fixed mode before restore AP's LVT thermal monitor register. Signed-off-by: Youquan Song Acked-by: Suresh Siddha Acked-by: Yong Wang --- arch/x86/include/asm/apicdef.h | 1 + arch/x86/kernel/cpu/mcheck/therm_throt.c | 12 +++++++----- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h index d87988b..34595d5 100644 --- a/arch/x86/include/asm/apicdef.h +++ b/arch/x86/include/asm/apicdef.h @@ -78,6 +78,7 @@ #define APIC_DEST_LOGICAL 0x00800 #define APIC_DEST_PHYSICAL 0x00000 #define APIC_DM_FIXED 0x00000 +#define APIC_DM_FIXED_MASK 0x00700 #define APIC_DM_LOWEST 0x00100 #define APIC_DM_SMI 0x00200 #define APIC_DM_REMRD 0x00300 diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c index 6f8c5e9..22c212a 100644 --- a/arch/x86/kernel/cpu/mcheck/therm_throt.c +++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c @@ -446,18 +446,20 @@ void intel_init_thermal(struct cpuinfo_x86 *c) */ rdmsr(MSR_IA32_MISC_ENABLE, l, h); + h = lvtthmr_init; /* * The initial value of thermal LVT entries on all APs always reads * 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI * sequence to them and LVT registers are reset to 0s except for * the mask bits which are set to 1s when APs receive INIT IPI. - * Always restore the value that BIOS has programmed on AP based on - * BSP's info we saved since BIOS is always setting the same value - * for all threads/cores + * If BIOS take over the thermal interrupt and set its interrupt + * delivery mode to SMI not fixed, it restore the value that BIOS has + * programmed on AP based on BSP's info we saved since BIOS is always + * setting the same value for all threads/cores. */ - apic_write(APIC_LVTTHMR, lvtthmr_init); + if ((h & APIC_DM_FIXED_MASK) != APIC_DM_FIXED) + apic_write(APIC_LVTTHMR, lvtthmr_init); - h = lvtthmr_init; if ((l & MSR_IA32_MISC_ENABLE_TM1) && (h & APIC_DM_SMI)) { printk(KERN_DEBUG -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/